Pro@programming.dev to Lemmy Be Wholesome@lemmy.worldEnglish · 7 个月前Be like Pluto.programming.devimagemessage-square86linkfedilinkarrow-up1951
arrow-up1951imageBe like Pluto.programming.devPro@programming.dev to Lemmy Be Wholesome@lemmy.worldEnglish · 7 个月前message-square86linkfedilink
minus-squaregandalf_der_12te@discuss.tchncs.delinkfedilinkarrow-up2·7 个月前The current classification is a mess. IMO, it should be a planet iff it can hold an atmosphere. I.e., it doesn’t actually have to have an atmosphere, but if it had any, it should have enough surface gravity to hold that one. If you define it that way, Pluto is just barely a planet.
minus-squarezqps@sh.itjust.workslinkfedilinkarrow-up9·7 个月前So whatever hypothetical density constitutes an atmosphere becomes the arbitrary line in the sand.
minus-squaregandalf_der_12te@discuss.tchncs.delinkfedilinkarrow-up2·7 个月前Well, yeah. But even so, it’s still better than the current definition. Many “planets” have not, in fact, cleared their orbit.
minus-squareturmacar@lemmy.worldlinkfedilinkarrow-up10·7 个月前Planet has never been very well delineated. The Sun was a “planet”. Ceres was a “planet”. When we find enough things to break up the classification, we make a new classification. Like “asteroid” or “dwarf planet” or “gas giant”.
minus-squarezqps@sh.itjust.workslinkfedilinkarrow-up1·7 个月前I don’t think the sun is in orbit around the sun.
minus-squareturmacar@lemmy.worldlinkfedilinkarrow-up1·edit-27 个月前That’s very heliocentric of you. The definition of ‘planet’ has changed a lot in the last few millennia.
minus-squareSpzi@lemm.eelinkfedilinkarrow-up1·7 个月前Similar to the arbitrarily defined density of other stuff in the same orbit. We need to draw lines somewhere to impose categories on nature.
The current classification is a mess.
IMO, it should be a planet iff it can hold an atmosphere. I.e., it doesn’t actually have to have an atmosphere, but if it had any, it should have enough surface gravity to hold that one.
If you define it that way, Pluto is just barely a planet.
So whatever hypothetical density constitutes an atmosphere becomes the arbitrary line in the sand.
Well, yeah. But even so, it’s still better than the current definition. Many “planets” have not, in fact, cleared their orbit.
Planet has never been very well delineated. The Sun was a “planet”. Ceres was a “planet”.
When we find enough things to break up the classification, we make a new classification. Like “asteroid” or “dwarf planet” or “gas giant”.
I don’t think the sun is in orbit around the sun.
That’s very heliocentric of you.
The definition of ‘planet’ has changed a lot in the last few millennia.
Similar to the arbitrarily defined density of other stuff in the same orbit. We need to draw lines somewhere to impose categories on nature.